Vacuum tube



- Oct. 27; 1936.

VACUUM TUBE Filed July 25, 1929 4 Shets-Sheet l INVENTOR flA/DEE LYLE Oct. 27, 1936. A. E. LYLE VACUUM TUBE Filed July 25, 1929 4 Sheets-Sheet 2 INVENTOR flA/DEEW C.

Oct. 27, 1936.

A. E. LYLE VACUUM TUBE Filed July 25, 1929 4 Sheets-Sheet 3 Oct. 27, 1936. A. E. LYLE VACUUM TUBE Filed July 25, 1929 4 Sheets-Sheet 4 \NVENTOR flA/DEEH E 1.1:

ATTO NEY Patented Oct. 27, 1936 UNITED STATES- PATENT OFFlCE VACUUM TUBE Andrew Ernest Lyle, Cambridge, Maaa, asslgnor to Raytheon Production Corporation, Newton, Mass., a corporation of Delaware Application July 25, 1929, Serial No. 381,018 8 Claims. (Cl. 250 -275) This invention relates to vacuum tubes and increase in efllciency and uniformity and a demethods of manufacturing the same. In the crease in cost of manufacturing. Another object manufacture of vacuum tubes, especially of the of this invention is to devise a tube which shall kind used in radio receiving sets, it is customary be sturdy and inherently self-supporting to main- 5 to assemble the electrode structure on supporttain the electrodes rigidly in their initial predeing wires sealed in a press. If at any stage of termined relative position. An additional object the assembly anything goes wrong. the entire is to devise a tube having more than the usual assembly must be discarded. Thus in the case three electrodes and which may be assembled as or a finished tube a defective seal necessitates a unit apart from the press and supporting wires.

discarding the entire structure. An additional object is to make such a tube with 10 In addition, the presence of the bulky glass the additional electrodes so compact and sturdy press with its depending stem at one end and that the characteristics of the tube will remain the projecting supporting wires at the other end substantially unchanged when subjected to semakes the task of assembling inconvenient, slow vere mechanical shock. Cther and additional and expensive. The presence of the glass supadvantages will become evident to those skillled 15 porting structure as web as the wires is not in the art, asthe description proceeds. conducive for quick and easy manipulation of Referring to the drawlngs,1 'igure 1 i an l v the assembly in w ld m ines Fu rmore. tion view of a preferred form of tube completely in assembling on the supporting wires sealed in assembled.

the glass pre operators Often force n a n Figure 2 is an elevation of the electrode assem- 20 the supporting wires out of their natural posibly of Figure 1 with certain portions cut away. tion to dispose them in some particular relation Figure 3 is a sectional view of the upper portion and in doing so are apt to cause minute cracks of Figure 2. at the seals producing latent defects which be- Figure 4 is a perspective vie of th electrode come noticeable when the entire tube is finished assembly. 25 and is being tested. Figure 5. is a sectional view of the bottom of In the manufacture and assembly of a tube in Figure 4. which more parts are required than in the ordi- Figure 6 is a view partly in section showing the nary three element tube, all of the above disadcathode grid and end m mat of an electrode vantages and problems become sharply accenstructure. 30 tuated. Thus in the manufacture of a shield Figure '7 is an elevation view of the cathode and grid tube, especially one having an equi-potential grid electrodes with a portion of one shielding cathode, the number of parts to be assembled grid and a bottom supporting plate, becomes so large and the work becomes so difli- Figures 8 and 10 are perspective views of insucult that. the presence of the glass press and lators used in the electrode construction. 5 V

supporting wires sealed therein results in an ob- Figures 9 and 11 are sectional views of Figures jectionable expense particularly in quantity pro- 8 and 10 respectively.

duction of such devices. In the manufacture of Fig. 9a. is an enlarged view of the upper leftthese tubes, the number of defective tubes present hand corner of Fig. 3.

when testing is solarge that the amount of mate- Fig. 9b is an enlarged fragmentary view Show- 40 rial discarded becomes an item of large proporing a portion of' the edge construction of the n us, retaining plates used on the ends of the electrode An object of this invention is to devise a tube assembly. in which the electrodes may be assembled as a Figure 12 is a sectional view on i2--l2 of Figunit independently of the press and supporting ure'6.

wires and when completely assembled may be Figures 13 and 14 are perspective views with conveniently and easily disposed on the supportparts cut away of two modifications. ing wires sealed in the press. with such a tube Referring more particularly to Figure 6, within if a defect appears on test, the assembly may be a cylindricalmetal member I is a heating memeasily remove'dfrom. the. supporting 'wires and her 2 extending the full. length of member I. 50

either one or the other member salvaged for later Member I forming a cathode is preferably of I nickel and has its treated with'suitable A further'obiect is to devise a tube which may chemicals such as oxides of alkaline earth metals be manufactured and assembled in a convenient, in order that when it is heated electron emission expeditious and cheap manner with a resultant occurs. Heater 2 may be of any suitable mate-- 55 rial such as tungsten, platinum or a nickel silicon alloy and is preferably spaced from member i throughout its entire length. If desired, heater member 2 may have its surface covered with a protecting insulating layer of kaolin or any other refractory material in order that no short circuits will occur in case the metal wall of I contacts with the coils of the heater. Leads 4, 5, and 6 are provided for the equi-potential cathode and heater respectively. The entire heater structure including the equi-potential cathode, heater and supports is more fully disclosed in my copending application, Serial No. 315,275, filed October 26, 1928.

The bottom of the cathode structure is suitably supported by an insulating member of lava or similar material. This insulating member comprises a circular portion 1 and an elongated base portion 8. As shown clearly in Figures 4-7 inclusive, insulator portion 1 is provided with apertures through which leads 4 and 6 of the cathode and heater respectively project. The other end 5 of the heater projects from the opposite end through the center of a disk Ill of mica, lava or any other desirable insulating material.

Between the two insulators is supported a control grid comprising a helical wire ll supported by diametrically opposed wires l2 and I3. This grid is made by well known machinery in the customary manner providing a structure which firmly maintains the coils of wire H on wires i2 and I3.

Wires l2 and I3 project through suitable apertures in insulator Ill. The bottom ends of i2 and I3 are preferably short enough so that they do not go beyond insulator 8 but fit into depressions in insulator 1, as shown in Figure 12.

The described electrode assembly is suitably supported at its lower end by dish shaped meminsulator in position her l5. This member has a centrally disposed aperture bounded by an upstanding flange i8 adapted to fit around the periphery of cylindrical insulator I. Adjacent the flange l6 are two apertures l1 and I 8 into which project wires l9 and 20. These wires support a helical shielding grid 22. .As shown in Figure 7, wires l9 and 20 proje'ct through suitable apertures in insulator member Ill. Wires l9 and 20 projecting through apertures l1 and I8 of plate l5 engage apertures 23 and 24 of base 8 of insulator l and maintain the by having the free ends of wires l9 and 20 bent over or suitably arranged so that the wires will not pull back through the insulator and plate. It is evident that wires I 9 and 20 pass through and directly engage plate l5 and thus make contact therewith.

Insulating member bly is suitably supported by a dish shaped member 25. This member may have a centrally disposed depressed portion 26, which portion has a central aperture bounded by a flange 21. The diameter of flange 21 is such as to fit shielding grid22 and be engaged thereby to help support the'latter. Disposed at diametrically opposing positions in plate 25 are two bosses 29 pressed outirom the plate when it is stamped. It will be noted that these bosses are stepped and comprise circular central portions 30 supported by small flanges which go into almost annular portions 3|. Portions 3! are surrounded by flanges and merge into member 25. These bosses cooperate with two similarly disposed bosses on the bottom plate l5 to support insulators and wires for the maintenance of an anode electrode 31.

As is well known, in a shield grid tube the ill at the top oi. the assemshielding grids are around the anode and between the grid and the anode and as a rule shield the ends of the electrodes. In this construction it is necessary to insulate the anode electrode and its supporting members from the two end dish shaped members l5 and 25 respectively. The insulation from plate 25 is accomplished by two insulating members 32 comprising a cylindrical portion 33 and a circular base portion 34. This is shown in Figures 8 and 9.

Portion 34 of insulators 32 which may be of lava or any other similar material, fit and are centered by portions 30 oi. bosses 2! 01' plate 25. In order to maintain the insulators in place at all times, I preferably slip over portion 33 of the insulators, metal washers 35 which are welded to member 25. These metal washers are preferably of such a size and shape as to fit portions 3| of bosses 29. In this wa it is evident that insulators 32 are maintained in desired relationship with plate 25.

Dish shaped member I5 as previously pointed out has two diametrically opposing bosses 24. These bosses are similar to bosses 29 oi plate 25 with the exception that the very centers of the bosses are punched out leaving apertures 25. Insulators 40 comprising a cylindrical portion 4| and a base portion 42 and having aperture 42 shown in Figures 10 and 11 are suitably disposed in the bosses in precisely the same manner as insulators 29, namely, by the provision of metal washers 35 clamping the insulators in the bosses and maintaining them in fixed relationhip. Between the two end members l5 and 25 is disposed an anode or plate electrode 3'! preferably of metal gauze. This is a circular electrode and is supported by diametrically opposing wires 44 and 45 welded thereto. The upper ends or these wires fit into holes in insulators 29 disposed in member 25. The lower ends of wires 44 and 45 are suitably supported by insulators 40 and project therethrough to the outside oi'the entire assembly. The diameter and length of anode 31 are such that the edges of the anode rest upon portions 33 and 4| of insulators 3-2 and 40 respectively. It is evident that the shade is thus thoroughly insulated from the two end dish members.

Dish shaped members i5 and 25 have their extreme peripheries bent to form flanges 48. At a plurality of spots oi? each of these members. ears have been cut out and the edge distorted for a purpose to be later described. It will be noted that at the inner edges of flanges 45, troughs 41 have been formed. Into both troughs fit the edges of electrode 48 which may be'o! gauze or solid metal. This electrode is the shielding electrode surrounding the anode and is tightly held by the two end members I5 and 25. Flanges 46 cover and form a 01 electrode 48 to maintain it in shape andin position-.- Ii. desired, the flanges and electrode may be welded together at several spots.

.To provide a lead to the bottomof the assembly for end 5 ofheater member 2, apertures maybe punched out in plates I 5 and 25 at registering points at any convenient position and insulators 49 disposed therein. A wire 50 may be threaded through and crimped at each end in order to retain it in place. A short connecting wire ll may then be welded 'from 5 to 50 to provide a through connection. Preferably the apertures in each or the members are so disposed as to bring wire 50 outside of anode I! and inside of electrode 45. If desired, heater 2 may be a double helix with both leads through insulator 1.

protecting rim for the edges correct position. By means aosacre In order to more thoroughly shield the control grid a metal member 53 may be fitted over portion 8 of insulator I where it lies against .the outside surface of dish member 85. This member is provided with an opening or slot 56 for leads 6 and b. and may be welded to the ends of wire it and Zdof the shield grid at ears 2i punched out therefrom and allowing the wires to protrude.

' It is evident that the entire electrode assembly forms a compact rigid and unitary construction. Because of the shaping of various parts, the parts fit together and tend to adjust themselves into of leads 5 and 8 as well as wire it, connection to the cathode and heating circuit maybe established. Either one of wires it and it may be chosen as a lead for connection to the plate circuit. Either one of wires 92 or ill projecting through top insulator it may be chosen as a connection for the control grid while connection to the shield grid may be de at any point on the metal enclosing structure.

To maintain the assembly firmly in place, I preferably crimp or weld tiny pieces of metal to various protrudingfree wire ends after assembly.

. The top of wire it protruding beyond insulator id is thus provided with a small piece of wire it welded to it. Thus the various wires projecting beyond insulator l2 may be crimped or suitably enlarged just beyond the insulator to prevent the parts from falling apart in the assembly.

In order to mount the entire assembly on apress, the peripheries of dish members it and 25 are provided with a plurality of projecting portions 55. .These portions have small ears 56 punched out therefrom forming apertures 51?. The apertures on both the opposing members It and 25 register. The entire electrodeassembly is suitably supported by slipping it over a plurality of wires 5i which are threaded through apertures ill of the assembly. Preferably these supporting wires 5i which are here shown as four in number, number may be chosen, are sealed into a press lMl preferably having a cruciform cross section as more fully described and claimed in the copending application of Paul T. Weeks, Serial No. 306,398, filed September 17, 1928.

This press has the various supporting wires sealed therein which are bent to meet the apertures of the electrode assembly. If desired, the press might be of such dimensions as to allow the use of straight supporting wires sealed into the corners of the glass. Additional wires llll, I02, 103, Ind are sealed in the intermediate portion of the press and are for the purpose of connecting with the heater, cathode and plate circuits.

It is evident that any two diametrically opposed wires of the supporting wires sealed in the press might be cut off short and used as connections to the cathode grid or anode, thus reducing central portion of the press.

the number of wires necessary to be sealed in the This would leave two diametrically opposed wires to support the entire electrode assembly. It is also possible to insulate three of the supporting wires from the shielding structure and use these for other connections.

The entire electrode assembly is suitably disposed in the usual glass tube 58 having the well known base 59 provided with standard prongs i05- ior engagement in the standard socket. For the particular type of tube shown, five prongs will be necessary, one for the equl-potential the cathode, while wire themselves.

course or emerges from the insulators.

although obviously any other two for the heater, one for the plate electrode and one for the shielding structure. The connections to the heater circuit are made by means of wires ibl and I02 connected to the leads 50 and 6 of the heater. Wire Hi3 connected to lead d of the cathode forms the connection ior tilt connected to standard the plate connection. The

cathode,

d5 of the plate forms wires till, 502, N3, ltd, and one of the standards bl are each connected respectively'to one of the prongs M5. The connection for the shielding structure may be very easily obtained by extending one of the supporting wires 51 through the seal to one of the prongs. Connection to the control grid may be made by means of wire ti welded to either one of the upper free ends of wires i2 and is of the control grid. This wire is sealed through the topof the tube and is soldered to a metal cap 62 cemented to the glass.

In the actual manufacture and assembling of the various electrodes, insulators and parts, the two end plates 85 and 25 are provided with their insulators 32, til and d9 maintained in place by metal washers welded to the plate members Shield grid 22. anode 3i and outer electrode M are then suitably positioned with respect to the two end plate members, the top and bottom ends of wires as and 20 being threaded through apertures formed in both of the end plate members and the other wires being threaded through or engaging their respective insulators. Flanges d6 are then suitably welded to outer electrode 48 at a plurality of spots. Wire 56 may be crimped at both ends where it The resulting structure is sturdy and rigid enough to maintain itself against all reasonable strains.

The cathode and control. grid assembly may then be very simply inserted by removing insulating disk Id of the assembly shown in Figure 6 and sliding the cathode and grid up inside of the shield grid. Apertures 23 and 2d of insulator 8 are aligned with the bottom of wires l9 and 20 of the shield grid projecting through bottom plate 55. All that is necessary is to thread lead 5, top

ends of wires-l2, l3, l9 and 20 through insulator Ill and push this down against the top of plate member 25. As soon as this is done the top ends of any one or all of the projecting wires may be suitably crimrmd or have a small piece of metal welded to maintain the insulator in place. Wire El may thereupon be welded to connect lead 5 and wire 50 of the heating circuit. Shield 53 may then be slipped over the bottom of insulator 8. The bottom ends of wires 19 and 20 will project through apertures punched in this shield and may be welded to ears 2i formed in the shield when the apertures are punched out.

It will thus be seen that I have devised a tube which may be very easily and cheaply assembled separately from the glass press and supporting wires. It is obvious that the assembly itself is a rigid unit which does not depend upon the press or supporting wires for the maintenance of the relative positions of the respective electrodes. When the tube is finished and tested it is evident that lf the press is found defective, the entire tube assembly may very easily be salvaged by pulling it from the supporting wires. In order to make salvage more expeditious, I prefer to weld only some of the ears 56 to the various supporting wires leaving others free. In case the structure must be pulled oif, the welded ears may very easily be clipped ofi leaving other cars for welding purposes. It is obvious that the ears are not necessary since the supporting wires may be welded to members l and 25 at the apertures.

By this construction it follows that if the oathode structure or' control grid are defective in any manner, they may very easily be replaced by metal to the top ends of either one or both of the control grid wires l2 and I3 and leave the other wires free. It is a very simple matter to clip ears 2| and pull the cathode and control grid assembly right out from the electrode assembly. In this way the cathode and grid portion of the electrode assembly may be salvaged if the rest of the assembly is defective or may be replaced if defective itself.

If desired only the extreme ends of the cathode heater leads 4 and 6 may be adapted to maintain the insulators together. It is evident that shield 53 maybe omitted and wires l2 and 13 of the grid project through the bottom of insulator 8. In such a case, the ends of these wires may be used to maintain the insulators in place.

Referring to Figure 13, a structure somewhat similar to the previously described structure is shown with the exception that only three electrodes are present. The cathode I has a grid ll supported by wires I2 and I3 in substantially the same manner as shown in Figures 6 and 7. The bottom insulator 1 may be the same as in Figure 6 and is disposed in substantially the same manner with respect to a bottom member 15. The upper ends of cathode and grid project through an insulating disc ill of mica or the like which rests on an apertured member 16 similar to the member in the preceding modification. Between dish members 15 and I6 is an anode 11 supported in substantially the same manner as the outer electrode of the shield grid assembly. The entire assembly has the customary, ears and apertures for detachable positioning on supporting wires of a press. It is evident that in order to standardize on parts, dish shaped members 15 and 16 might actually be the same as members l5 and 25 of the shielded grid structure. In such case there would be no necessity for disposing the extra insulators and electrodes within the structure.

In Figure 14, I have shown another modification in which the two end members are insulators and in which the cathode is of the filamentary type. In this modification a V shaped cathode 80 has its ends suitably supported at clips 8| and 82 fixedly positioned in an insulator member 83. The apex of the V is firmly maintained in position by spring member 84 in the upper insulating plate 85. A helical grid 86 is suitably supported between wires 81 and 88, the latter projecting through suitable apertures in members 83 and 85. These wires may be crimped as at 88 in order to maintain insulating members 83 and 85 against each other. Surrounding the grid is a rectangular anode 90 which may be fabricated from four blanks and curled at the corners as shown at ill in the usual manner. The anode preferably has small cars 92 which project through slots 93 in insulating plate 83 and 85. These ears are bent fiat and tend to anchor the end plates firmly against the electrodes.

It is evident that because of the rigidity of anyone of the electrode assemblies it is unnecessary to do more than to support the entire weight of the assembly. In prior devices it has been cusa,oss,47e

necting wires from these supporting wires to the various electrodes. In the case of the structure of Figure 13 and of the other figures, it is very simple to insulate one or more of the supporting wires from the metal shielding structure. In order to do this the insulator shown in Figures 10 and 11 may be very eifective in apertures 51 of the end members. In the constructions of the prior art such an eilicient use of supporting members as leads was practically impossible since the supporting wires were directly welded to the various electrodes. To insert insulators between the supporting wires and the electrodes was burdensome and expensive. o,

It is evident that the circular electrodes of the structure shown in Figures 2 and 4 as well as in Figure 13 may be rectangular as in Figure 14. It is also evident that the end members of insulating material in Figure 14 may be circular and have circular electrodes between them as shown in Figure 13. It is obvious that cathode I of Figure 13 may be very simply replaced by a filamentary cathode.

My invention is characterized by the broad feature of an electrode assembly which may be removed or replaced as a unit on the press of a vacuum tube. In addition the assembly itself includes a portion which may be very simply removed as a subsidiary unit to replace defective or undesirable parts. In its broader aspects my invention is characterized by the provision of a plurality of electrodes, the ends of which are firmly maintained with respect to each other to make a unitary compact structure. More specifically the ends are supported by members which may if desired be fiat or circular or metallic. The outermost electrode has its edges firmly maintained by end engaging members.

In another aspect my invention is characterized by the fact that the ends of some electrodes engage insulators to'maintain them in position and that there are means for maintaining all of the electrodes in desired relative position to each other and the insulators and said means cooperate in such a maner that the insulators maintain said means in desired relative position to each other. The means which will maintain the insulators together will maintain the entire assembly intact. The ends of anyone or more of the electrodes piercing said insulators may thus carry at their extreme ends the means for maintainin the entire electrode assembly intact.

I claim:

1. An electrode assembly comprising a cathode, a grid surrounding said cathode, insulators engaging both ends of said electrodes and maintaining them in desired position, an anode surrounding said grid, two fiat metal members at each end of the anode and engaging said insulators, said fiat metal members being provided with a plurality of recesses, additional insulators mounted in said recesses, said insulators insulating said anode from said fiat members.

2. An electrode assembly comprising a cylindrical cathode, a heating member within said cathode, a grid surrounding said cathode, a shield anaem a electrode surrounding said grid, an insulator at each end of said electrode maintaining said electrodes in desired relationship to each other, an anode surrounding said shield electrode, and an additional electrode surrounding said anode, a pair of metal members engaging each-o! said insulators, means for insulatingly supporting said anode between said pair of metal members, and means for maintaining said metal members in {desired relationship to each other.

3. In an electrode assembly whereby a cathode, grid and anode are maintained as a rigid independent unit, a metal plate provided with a plurality of bosses, insulators set into said bosses, and metal washers maintaining said insulators in said bosses.

4. An electrode assembly comprising an indirectly-heated cathode, a grid surrounding said cathode, a shield electrode surrounding said grid, an insulator at each end of said electrodes maintaining said electrodes in desired relationship to each other, an anode surrounding said shield electrode, and an additional electrode surrounding said anode, a pair of metal members engaging said insulators, means for insulatingly supporting said anode with respect to said pair oi metal members, and means for maintaining said metal members in desired relationship to each other.

5. An electrode assembly comprising an indirectly-heated cathode, a grid surrounding said cathode, an insulator at each end of said electrodes maintaining said electrodes in desired relationship to each other, an anode surrounding said grid, and a pair of metal members engaging said insulators, means ior insulatingly supporting said anode with respect to said pair of metal members, and means for maintaining said metal members in desired relationship to each other.

6. A, space discharge device comprising a cathode, a grid surrounding said cathode, a shield electrode surrounding said grid, an insulator, at each end of said electrodes maintaining said electrodes in desired relationship to each other, an anode surrounding said shield electrode, a pair of metal plate members engaging said insulators, said anode being insulatingly supported by said pair of metal plate members, and means for maintaining said metal plate members in desired relationship to each other.

'7. A space discharge device comprising a cathode, a grid surrounding said cathode, a shield electrode surrounding said grid, an insulator at each end of said electrodes maintaining said electrodes in desired relationship to each other, an anode surrounding said shield electrode, a shielding member surrounding said anode, a pair of metal plate members engaging said insulators, said anode being insulatingly supported by said pair of metal plate members, and means for maintaining said metal plate members in desired relationship to each other.

8. A space discharge device comprising a cathode, a grid surrounding said cathode, a shield electrode surrounding said grid, an insulator at each end of said electrodes maintaining said electrodes in desired relationship to each other, an anode surrounding said shield electrode, a pair of metal plate members engaging said insulators, said anode being insulatingly supported by said pair of metal plate members, said metal plate members being electrically and mechanically connected together.

ANDREW ERNEST LYLE. 

